Shock wave application of twist-off crowns

ABSTRACT

This apparatus applies twist-off crowns to the tops of bottles by forming the crowns in place. A cap blank is placed over the threaded top of a bottle. A combustible gas is placed in a confined space above the cap blank. The combustible gas is ignited and the cap blank forms onto the bottle top making a functional twist-off cap from the crown blank. When the combustible gas is ignited, a compressive wave strikes the cap blank and forms it to the twist-off top.

United States Patent 91 Erlandson Jan. 23, 1973 1 SHOCK WAVE APPLICATION OF 3,228,222 H1966 Maia ..72/56 TWIST-OFF CROWNS I I I Primary Examiner-Travis S. McGehec [75| Inventor. PlulM. Erlandson, Palos Park, Ill. Ammey AmericuH Mitchel" jowph E Kerwin and [73] Assignee: Continental Can Company, Inc., William Dillmflnn New York, NY. [57] ABSTRACT [22] Filed: Nov. 2, 1970 This apparatus applies twist-off crowns to the tops of PP N04 86,000 bottles by forming the crowns in place. A cap blank is placed over the threaded top of a bottle. A combustible gas is placed in a confined space above the cap 52 I 1 U 8 Cl 53/42 29/421 blank. The combustible gas is ignited and the cap 51 I 1 Cl B65 blank forms onto the bottle top making a functional 1 I! I twist off from the crown l k w the [58] Field Of Search ..53/42, 329; 72/56 bustible gas is ignited, a compressive wave strikes the cap blank and forms it to the twist-off top.

[56] References Cited 12 Claims, 7 Drawing Figures UNITED STATES PATENTS 3,252,312 5/1966 Maier ..72/56 PATENIEU JAN 2 3 I975 SHEET 1 OF 3 EXHAUST EXHAUST INVENTOR PAUL M. ERL ANDSON ATT'Y PATENTED JAN 2 3 I973 SHEET 2 BF 3 INVENTOR PAUL M. ERLANDSON Q/im W PATENTEUmzs I975 SHEET 3 [IF 3 EXPLODE ll Him IXIHF i| INVENTOR PAUL M. ERLANDSON BY 7 a ATT'Y SHOCK WAVE APPLICATION OF TWIST-OFF CROWNS This invention relates to the forming of crown blanks onto bottles having twist-off tops. Especially this invention relates to the forming of hollowed ductile objects onto the upper nicks of bottles.

Twist-off caps usually are formed at a site remote from the place where they are applied to the bottle neck. The formed twist off caps are turned onto the bottle neck in one operation and as a next operation the detent means are formed over an annular bead integrally formed on and projecting outward from the outer bottle neck. This involves several operations with consequent expense and danger of breakage in handling.

My invention has to do with the forming of ductile materials around the top of the bottle necks to form a twist-off cap. The bottle cap may have a sealing element such as a rubber or plastic disc-like sealing liner in its end so that when the cap is formed around the bottle neck the cap of the bottle fits snugly onto the bottle neck to cause an air tight seal.

This invention is essentially one involving air contamination as well as ease of packaging.

It is an object of this invention to form cap twist-off caps onto bottle tops at a high speed.

It is another object of this invention to form bottle caps onto bottle tops with a minimal number of operational steps.

It is a further and final object of our invention to provide a system which functions on plastics, non-magnetic metals and magnetic metals with roughly equal efficacy.

These and other objects and advantages of the invention will be more readily apparent from the description of the preferred embodiments of the invention taken in conjunction with the description of the drawings in which:

FIG. 1 shows a schematic view with parts shown in section revealing the general details of an apparatus for applying a shock wave to a single preform cap.

FIG. 2 shows a schematic fragmentary elevational view of an apparatus of FIG. 1 with the bottle and preformed cap inserted into the shock tube.

FIG. 3 shows a schematic view of another embodiment of my device in which a multiplicity of shock tubes are mounted in series.

F IG. 4 shows the valve in vacuum position.

F IG 5 shows the valve in position to admit combustible gas.

F lG. 6 shows the valve in position to admit oxygen.

F IG. 7 shows the valve in position at the explosion point.

Stated briefly, this apparatus applies a twist-off cap to an external thread on the top of a bottle by applying a compression wave to a cap preform mounted on the bottle top. A combustible gas and oxidizer are placed in the confined space above the cap preform. When the combustible gas is ignited, then the cap preform forms onto the bottle top making a functional crimped cap. Optionally, the twist-off cap may have yet an additional feature. A detent means with bridges to the cap top is formed onto an annular bead which projects outwardly from the bottle neck. 3.

The drawings disclose seven figures which depict two principal embodiments of my apparatus.

The simpliest embodiment of my invention is shown schematically in FIG. 1 where bottles 1 are mounted on a support 2 which passes a capping station 3. The bottles 1 are in spaced relationship one to the other and are moved step-wise or in some other fashion such as by continuous motion to the capping station. Once at the capping station, the neck 4 of the bottle is transported up into a chamber 5 which maybe in the form of a shock tube 6. The end of the shock tube may be an annular disc having an opening 9. Each bottle on the support 2 has a preform 7 over the end 8 of the bottle. The preform is first inserted into the shock tube through the opening 9 in the annular disc 10 as shown in FIGS. 1 and 2. At the capping station a plunger 1 1 is mounted in the support 12'. The preform is made of metal, plastic, or the like. Bottle 1 is thrust up into the shock tube by the plunger. The preform and the bottle neck are inside the shock tube when a spark is ignited by the igniter 12 which has two spark posts 13. The plunger 11 may be moved upward in a suitable manner being actuated by solenoid, fluid motor or the like.

When the spark is ignited, a shock wave is caused by the high burning rate of the combustible material. This material is under some pressure. A shock wave is generated and strikes the preform cap 7 after the explosion. The preform cap is shrunk down onto the top of the bottle or jar (FIG. 2). It is then an easy matter to extract it through the flexible lip 14. While the cap of the bottle or jar is being extracted through the flexible lip the following series of events happens. The combustible residues are evacuated in large part from the shock tube chamber and at the same time a new bottle is inserted into the shock chamber. Optionally, the step of vacuum removal of combustible residues may be omitted. Then combustible gas and oxidizer is again conducted into the shock chamber and mixed together in preparation for a spark arc.

The valve 15 shown to the right is a rotary type valve which connects fluid conduit 16 by selective communication to one of two or more sources. A conduit 17 connects to the combustible gas. The conduit 18 connects to the oxygen or whatever oxidizer is used, and a conduit 19 may connect to a vacuum source for sweeping out the exploded gas products. The port 20 connects to the ambient air to allow the explosion products to pass out directly and conduit 21 leads to a place where it is convenient to exhaust the combustion products.

The nature of the compression or shock wave which operates to form the twist-off cap preform is such that the compression wave forms the twist-off preform blank without itself escaping appreciably through the various orifices such as the exhaust conduit 21 or the space 22 between the bottle neck and the flexible lip of the chamber. That is to say, the space 22 between the bottle neck and the flexible lip 14 offers considerable resistance or impedence to the passage of the compression wave. In this way the compression wave exerts its complete force against the twist-off cap preform and contours this preform nicely onto the top of the bottle. The twist-off cap 23 is formed onto the top of the bottle as shown in FIG/2. Now the bottle and cap may be withdrawn from chamber 5 with relative ease since the outer diameter of the formed cap is much smaller than the outer diameter of the unformed cap.

In the production apparatus another embodiment may be used. FIG. 3 shows a series of shock sections in which the the bottle 1 enters a long chamber 24 having a multiplicity of individual shock sections 25. These sections are separated from each other by a series of partitions 26 which extend downward to the cap height. Partition 26 may be flexible or a fixed membrane. A conveyor 27 carries a series of bottles. The chamber 25 may be any selected length to accommodate say, ten bottles. The trough shaped part 28 of the chamber has a slot 29 down the length of its bottom. Thus the chamber may cap ten bottles each time that there is an explosion. The operation of this device is as follows. When ten uncapped bottles with cap preforms on their tops are in the chamber, then the explosive gas mixture in each shock section 25 is ignited and the cap preforms are formed onto the individual bottle tops. During this time period the shock wave passes from the spark cap down to form the preform twist-off cap onto the bottle neck. After the cap is formed onto the bottle neck the bottles continue along the support and are replaced by ten more bottles lined in series in the shock chamber. While the replacement is taking place, the space above the bottle tops is evacuated and the exhaust gas is replaced with an explosive gas mixture. When the tenth bottle comes into place in its respective section, a spark is ignited at each section 25 of the long chamber and each cap blank is formed onto its respective bottle top. Each successive group of bottles having fully formed caps is indexed out to be replaced by a new batch. Because of the speed of the shock wave, it is not necessary to stop the bottles in place. Thus, the bottles may be fed continuously through a tunnel chamber and as a successive group of bottles having blank caps arrive in the chamber, the chamber is fired and the cycle is repeated time after time.

FIGS. 4 to 7 are shown in reference to FIGS. 1 and 2.

It is understood that operation of the valve for each section in FIG. 3 is the same as shown in FIGS. 4 to 7 and like parts are given like numbers. Operation of the embodiment shown in FIG. 3 is accomplished by a series of valves connected so as to rotate in unison with one valve 12 for each section 25 of the long chamber. The igniter l2 fires when the combustion mixture is in each section and a bottle top with an preformis in each section of the long chamber. The vacuum position 19 shown in FIG. 4 may or may not be used in connection with this apparatus. However, if it is used in this apparatus, then it is used to draw all expanded exhaust gases out of the shock chamber. Next, the valve turns to the combustible gas position 17 wherein a combustible gas under pressure is delivered to the interior of the shock section 25, as shown in FIG. 5.

After this, the valve is rotated to oxygen position 18' (FIG. 6) and an oxidizer is passed through the valve and conduit into the shock chamber. Any oxidizing material suitable to the use may be passed into the shock chamber. A discussion of possible explosive gases and oxidizers for use is found in the patentto C.

where the rest of the gas is brought out and the operation goes through the cycle as noted above.

The advantages of this operation are numerous and some of them are listed here. Some advantages are:

This apparatus is capable of high speed because I there are few operational steps;

E. Maier, U.S. Pat. No. 3,252,3l2 and assigned'to the assignee of this invention.

As the gas ignites, the valve is turned to its explode position 20. Because the compression wave which does the work of forming the cap, does not pass out through the space 22 between the bottle neck and the flexible There is no physical contact of solid objects with the preform cap;

There is no need for close seals between the bottle and the shock tube or the elongated chamber;

Cap decoration is not damaged;

This device functions well with any somewhat ductile material.

The foregoing is a description of an illustrative embodiment of the invention, and it is applicants intention in the apended claims to cover all forms which fall with the scope of the invention.

What is claimed is: a

l. A method of shaping a twist-off cap comprising the steps of:

placing a cap preform onto the upper neck of a bottle,

placing said cap preform and upper neck of said bottle in an enclosure,

introducing an ignitable gas into the enclosure, and

igniting said ignitable gas to form a combustion product and generate a compression shock wave to form the twist-off cap onto the upper neck of the bottle.

2. A method of shaping a twist-off cap as set forth in claim 1 comprising the further step of:

removing said bottle and formed cap from said enclosure.

3. A method of shaping a twist-off cap as set forth in claim 1 in which said step of placing said cap preform and upper neck into an enclosure comprises the steps of:

moving said cap preform and upper neck of said bottle to a position directly under an opening in the enclosure, and

thrusting said cap preform and upper neck of said bottle into said opening.

4. A method of shaping a twist-off cap as set forth in claim 1 in which said step of introducing an ignitable gas into the enclosure comprises the steps of:

introducing combustible gas into said enclosure, and

adding an oxidizer into said enclosure.

5. A method of shaping a twist-off cap as set forth in claim 4 comprising the further step of:

evacuating said combustion products from said enclosure after said ignitable gas is burned. 6. A method of shaping a twist-off cap as set forth in claim 5 in which said step of evacuating said combustion products comprises the steps of:

connecting said enclosure to the ambient air at the same time as said step of igniting said gas, and

subsequently connecting said enclosure to a vacuum source whereby all combustion products are swept out of said enclosure.

7. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks comprising:

a long chamber,

a slot formed in the bottom of said long chamber extending from a first end of the long chamber to a second end of said chamber,

a conveyor for transporting bottles,

a plurality of partitions extending transversely across said long chamber to divide said chamber into sections,

a cut out portion in each said partition to form a passageway along the length of the slot whereby the necks of said bottles may have free passage through said slot and partitions from one end of the chamber to the other,

a plurality of fluid conduits each having a first and second end, each said first end of each fluid conduit being connected to the interior of a separate section,

a plurality of valves each having a plurality of ports,

said second end of each fluid conduit being connected to a first port of one of said plurality of valves, and

means for igniting an explosive mixture in each said section of said chamber.

8. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 7 in which each of said plurality of valves comprises:

rotary valve means each having one port which is selectively connectible to one of a plurality of ports on the exterior of said valve means.

9. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 8 in which said long chamber comprises:

a rigid elongated trough shaped member having a slot coextensive with the length.

10. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 9 in which said long chamber further comprises:

a rigid member mounted across the top of said trough shaped member, and

port means for each shock section formed in the rigid member and each port means connected to said first end of each said fluid conduit.

11. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 10 further comprising:

conduit means connecting a second port in each said valve to a source of combustible gas,

conduit means connecting a third port of each said valve to a source of oxidizer, and

a fourth port in each said valve, leading to the ambient air.

12. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 1 1 further comprising:

conduit means connecting a fourth port of each said valve to a vacuum source whereby expanded gases are drawn out of said chamber sections. 

1. A method of shaping a twist-off cap comprising the steps of: placing a cap preform onto the upper neck of a bottle, placing said cap preform and upper neck of said bottle in an enclosure, introducing an ignitable gas into the enclosure, and igniting said ignitable gas to form a combustion product and generate a compression shock wave to form the twist-off cap onto the upper neck of the bottle.
 2. A method of shaping a twist-off cap as set forth in claim 1 comprising the further step of: removing said bottle and formed cap from said enclosure.
 3. A method of shaping a twist-off cap as set forth in claim 1 in which said step of placing said cap preform and upper neck into an enclosure comprises the steps of: moving said cap preform and upper neck of said bottle to a position directly under an opening in the enclosure, and thrusting said cap preform and upper neck of said bottle into said opening.
 4. A method of shaping a twist-off cap as set forth in claim 1 in which said step of introducing an ignitable gas into the enclosure comprises the steps of: introducing combustible gas into said enclosure, and adding an oxidizer into said enclosure.
 5. A method of shaping a twist-off cap as set forth in claim 4 comprising the further step of: evacuating said combustion products from said enclosure after said ignitable gas is burned.
 6. A method of shaping a twist-off cap as set forth in claim 5 in which said step of evacuating said combustion products comprises the steps of: connecting said enclosure to the ambient air at the same time as said step of igniting said gas, and subsequently connecting said enclosure to a vacuum source whereby all combustion products are swept out of said enclosure.
 7. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks comprising: a long chamber, a slot formed in the bottom of said long chamber extending from a first end of the long chamber to a second end of said chamber, a conveyor for transporting bottles, a plurality of partitions extending transversely across said long chamber to divide said chamber into sections, a cut out portion in each said partition to form a passageway along the length of the slot whereby the necks of said bottles may have free passage through said slot and partitions from one end of the chamber to the other, a plurality of fluid conduits each having a first and a second end, each said first end of each fluid conduit being connected to the interior of a separate section, a plurality of valves each having a plurality of ports, said second end of each fluid conduit being connected to a first port of one of said plurality of valves, and means for igniting an explosive mixture in each said section of said chamber.
 8. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 7 in which each of said plurality of valves comprises: rotary valve means each having one port which is selectively connectible to one of a plurality of ports on the exterior of said valve means.
 9. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 8 in which said long chamber comprises: a rigid elongated trough shaped member having a slot coextensive with the length.
 10. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 9 in which said long chamber further comprises: a rigid member mounted across the top of said trough shaped member, and port means for each shock section formed in the rigid member and each port means connected to said first end of each said fluid conduit.
 11. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as Set forth in claim 10 further comprising: conduit means connecting a second port in each said valve to a source of combustible gas, conduit means connecting a third port of each said valve to a source of oxidizer, and a fourth port in each said valve, leading to the ambient air.
 12. An apparatus for simultaneously forming a plurality of caps onto a plurality of bottle necks as set forth in claim 11 further comprising: conduit means connecting a fourth port of each said valve to a vacuum source whereby expanded gases are drawn out of said chamber sections. 